我正在编写一个 iPad 应用程序,它需要从服务器下载许多但相当小的 .json 和 .jpg 文件。
所以票价我这样做是这样的:
///Function to allow for recursive calls to syncronize inspections sequentially.
func getInspection(ip: String, view: sensorSyncronizationDelegate, idarr:[IdData], appDelegate: AppDelegate){
let inspectionID = idarr[0]
var newArr = idarr
//A task is created for each inspection that needs to be downloaded, and the json is parsed and added to the database.
if self.session != nil {
let inspectionURL = NSURL(string: "http://\(ip)/inspections/\(inspectionID.id!).json")
let inspectionTask = self.session!.dataTaskWithURL(inspectionURL!) { (data, response, error) in
//If data is nil, end the task.
if data == nil {
view.setInspectionSyncCompleted()
view.completion("Error: Timeout please ensure Instrument is on, and attempt syncronization again")
print(error)
return
}
//if newArr is NOT empty make a recursiv call to getInspection()
newArr.removeAtIndex(0)
if !newArr.isEmpty{
self.getInspection(ip, view: view, idarr: newArr, appDelegate: appDelegate)
}else{
self.syncMisc(ip, view: view)
}
(我一直在使用 dataTaskWithURL)
这就是会话的设置方式:
var session : NSURLSession?
///Function to set up various http configurations, and call the various syncronization functions.
func syncWithSensor(view: sensorSyncronizationDelegate, ip: String!){
//Session Configuration
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
config.allowsCellularAccess = true
config.timeoutIntervalForRequest = 30
config.timeoutIntervalForResource = 60
config.URLCache = nil
//Authentication config
let userpasswordString = "MAMA:PassWord"
let userpasswordData = userpasswordString.dataUsingEncoding(NSUTF8StringEncoding)
let base64encodedCreds = userpasswordData!.base64EncodedStringWithOptions([])
let authString = "Basic \(base64encodedCreds)"
config.HTTPAdditionalHeaders = ["Authorization" : authString, "Connection" : "Upgrade"]
session = NSURLSession(configuration: config)
//Check if for some reason ip is invalid
if ip == nil{
view.setSeriesSyncCompleted()
view.setTemplateSyncCompleted()
view.setInspectionSyncCompleted()
view.completion("Error: Failed to connect to ***, please reset connection")
}
//Call the inspection sync function.
syncInspections(ip, view: view)
}
//Function to respond to authentication challenges.
func URLSession(session: NSURLSession, task: NSURLSessionTask, didReceiveChallenge challenge: NSURLAuthenticationChallenge, completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential!) -> Void) {
let credential = NSURLCredential(user: "MAMA", password: "PassWord", persistence: .ForSession)
completionHandler(NSURLSessionAuthChallengeDisposition.UseCredential, credential)
}
是的,它工作得很好。我可以在 22 秒内下载 280 多个文件(.json 和 .jpg),这很不错,但对于用户来说,查看下载计数器需要很长时间。
计划是,拥有更多……所以我真的需要一种方法来更快地做到这一点。
如果需要,我可以提供更多我正在使用的代码。
提前致谢 :)